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1. Function

This circuit monitors various tones, such as (1) DTMF tone, (2) Alarm/Beep/Key tone/Bell.

2. Signal Path

a. DTMF MONITOR

(Speaker Operation)
Refer to CHECK SHEET.
(Handset Operation)
Refer to CHECK SHEET.

b. ALARM/BEEP/KEY TONE/BELL

Refer to CHECK SHEET.

1. Function

When TAM is connected to this unit, the unit receives documents for FAX calls or the external TAM records a voice message
automatically.

2. Circuit Operation

The TAM INTERFACE circuit consists of transformer (T200), amplifier (IC204) analog ASIC (IC209), MODEM (IC600) to
detect the other party CNG signal, and RLY200 to separate EXT.TAM.

a. CNG signal detection circuit

The CNG signal from the other party’s FAX is detected in MODEM IC607 (digital board).
(Signal path)
Refer to CHECK SHEET(P.158).

b. Remote receiving

This is the parallel-connected DTMF signal for the TEL or EXT.TEL mode between T and R. When the other party is a
FAX, the unit switches to FAX receiving.
(Signal Path)
Refer to CHECK SHEET(P.158).

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The scanning block of this device consists of a control circuit and a CIS (contact image sensor), and AFE (Analog Front End)
include A/D Converter.

When an original document is inserted and the start button pressed, pin U5 of IC600 goes to a low level and the transistor Q613
turns on. This applies voltage to the CIS. The CIS is driven by each of the SCSI, SCCLK signals output from IC600, and the original
image illuminated by the LED to output an analog image signal. The analog image signal is input to the AFE on VINP (20pin of
IC612)  and converted into 16-bit data by the A/D converter inside IC612. Then this signal undergoes digital processing in order to
obtain a high-quality image.

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1. Functions

All driving force of printer engine part is supplied by this engine motor. Engine motor is controlled to rotate at constant
speed during printing and copying mode.

2. Motor operation

<Start operation>
In order to start the motor rotation, following 3 signals are supplied from IC604.
1. SS signal
Output pin: Pin 120/Output Signal: “H”
This signal is inverted by transistor Q634, and supplied to motor as “Start/Stop” signal.
2. Clock signal
Output pin: Pin 121/Output Signal: Pulse
Pulse frequency: approx. 1.9 KHz (at the normal printing speed)
Pulse frequency: approx. 0.5 KHz (at the half printing speed)
3. Break signal
Output pin: Pin 122/Output Signal: “L”

When motor reaches constant speed, low level signal is output from the motor.  
as “Lock detect” signal.
if this “Lock detect” signal does not become low level within predetermined period after “SS” signal becomes "H" level, or if
“Lock detect” signal becomes  “H” level during rotating, it is judged that “Motor Error” occurred.

Timing Chart of Start operation

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<Stop operation>
In order to stop the motor rotation, following 2 signals are supplied from IC604.
1. SS signal
Output pin: Pin 120/Output Signal: “L”
Consequently “Start/Stop” signal becomes “H”.
2. Break signal
Output pin: Pin 122/Output Signal: “H”
Motor stops rapidly by changing the “Break” signal from “L” to “H”.

Timing Chart of Stop operation